title: Scanning tunneling microscopy of a liquid crystalline phase of poly((dA-dT).(dA-dT)) induced by a histone H1 peptide.
abstract: In this report, we present the first observations of uncoated poly((dA-dT).(dA-dT)) molecules organized in a liquid crystalline phase induced by the binding of a histone H1 peptide. The effect of the peptide on the polymer condensation is clearly illustrated on the large-scale STM images which reveal a well defined spacing between parallel DNA helices. High resolution images of rare isolated molecules of poly((dA-dT).(dA-dT)) exhibit two sets of helical pitch values, 6 and 7.5 nm. While the lower value can be correlated with the pitch of poly((dA-dT).(dA-dT)), the larger one may arise from peptide binding in the polymer minor groove.
authors.affiliation: CEMES-LOE/CNRS, Toulouse, France.
authors.forename: R
authors.initials: R
authors.lastname: Coratger
authors.forename: A
authors.initials: A
authors.lastname: Chahboun
authors.forename: F
authors.initials: F
authors.lastname: Ajustron
authors.forename: J
authors.initials: J
authors.lastname: Beauvillain
authors.forename: M
authors.initials: M
authors.lastname: Erard
authors.forename: F
authors.initials: F
authors.lastname: Amalric
mesh_terms: D003460:Crystallization; D006657:Histones / Q000648:ultrastructure*; D008854:Microscopy, Electron; D016252:Microscopy, Scanning Tunneling; D011067:Poly dA-dT / Q000737:chemistry*
chemical_list: D006657:Histones; D011067:Poly dA-dT